A 26 year-old sexually active female presents to her family practitioner complaining of abdominal distension, nausea, and vomiting. Her last menstrual period was 16 weeks ago, which she attributes to her recent increase in exercise. Nevertheless, her physician requests a urine sample to measure levels of a glycoprotein secreted by which of the following structures?
Amnioblast
Cytotrophoblast
Mesonephros
Syncytiotrophoblast
Wharton’s jelly
Correct answer
Syncytiotrophoblast
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correct answer: D
The patient’s symptoms are likely secondary to a hydatidiform mole, which characteristically features painless vaginal bleeding during the second term and extraordinarily high levels of human chorionic gonadotropin (hCG), a glycoprotein secreted by the syncytiotrophoblast.
hCG is an early marker of pregnancy, appearing 6-12 days after implantation of the blastocyst. Its levels rise exponentially during the first trimester, peak at weeks 7-10 during the luteo-placental shift, and decline gradually in the following weeks.